Detachable toolholder



Feb. 22, 1955 c. H. SNYDER ETAL 2,702,712

DETACHABLE TOOLHOLDER Filed Sept. 8, 1949 United States Patent 4Oli ice2,702,712 Patented Feb. 22, 1955 DETACHABLE T OOLHOLDER Clilord H.Snyder, Dormont, Pa., and Douglas A. Turner, Salem, Ohio, assignors, bymesne assignments, to The Cfolnlilol Company, New Lexington, Ohio, acorporation o O io Application September 8, 1949, Serial No. 114,553

1 Claim. (Cl. 279-79) This invention relates generally to tool holders,and more particularly to holders for detachably retaining bits such asmining machine bits.

The principal object of this invention is the provision of a tool holderthat is adapted for quickly changing the tool therein without the use ofspecial tools for such purpose. This invention also contemplates astrong support for transmitting heavy loads subjected to the toolwithout stressing or otherwise interfering with the tool retainingmeans.

This invention is particularly advantageous for detachably supportingcoal chipping bits on cutting bars, or rotary coal chipping headswherein the bits are radially spaced, progressively receding axially andare disposed angularly to the plane of the coal face. The simultaneousforward feed and rotation ofthe coal chippinghead moves the bits alongspaced concentric helices. The traveling bits thus constantly cross thehorizontal and vertical cleavage planes of the coal causing it to chipout usually ahead of the advancing bits. The varying pressure loadproduced by the character of the coal and other substances encounteredin digging is transmitted from the teeth through a shoulder and stem toa socket fixed on the chipping head and thence through the head androtary shaft on which it is supported. This stem is disposed normally tothe shoulder from which the teeth extend and can be constructedmaterially stronger than the teeth. The juncture of the stem andshoulder and the tips of the teeth may be the weakest links in thestructure, but are designed to be the first break. The socket has yet tobreak in service even though some play is desirable between the stem ofthe bit and the socket in which it ts.

The means of locking the bits in thel socket represent an importantobject of this invention. This lock is obtained by a spring arm havingan inturned tongue that passes through a window in the socket or the bitand extends into a pocket in the bit. This pocket being preferablylarger than the tongue and spaced from the bit shoulder so that it willfunction only as a retaining means. This spring locking arm is mountedto be shielded from contact with the coal and has been found to beundisturbed even when the teeth or stem of the bit is broken. However,the spring locking arm may be readily priecl up to permit withdrawal ofthe bit by a knife, screw driver, or other similar pointed instrument athand. Upon prying up the tongue from the pocket of the bit, the lattermay be readily withdrawn from the socket and replaced.

Other objects and advantages appear hereinafter in the followingdescription and claim.

The accompanying drawings show, for the purpose of exempliiicationwithout limiting the invention or claim thereto, certain practicalembodiments of this invention wherein:

Fig. l is a plan view of the socket comprising this invention having amining machine bit secured therein;

Fig. 2 is a sectional view taken on the line 2 2 of Fig. l;

Fig. 3 is a transverse sectional view taken on the line 3 3 of Fig. l;

Fig. 4 is a transverse sectional view taken on the line 4 4 of Fig. 2;

Fig. 5 is a View partially in section showing another type of socket andlocking means;

Fig. 6 is a side elevation of the structure shown in Fig. 5;

Fig. 7 is a transverse sectional view taken on the line 7 7 of Fig. 5,

Fig. 8 is a transverse sectional view taken on the line 8 8 of Fig. 6;

Fig. 9 is a top plan view of a third type of detachable tool holder;

Fig. l0 is a sectional View taken on the line 10 10 of Fig. 9;

Fig. ll is a transverse sectional view taken on the line 11-11 of Fig.9;

Fig. l2 is a transverse sectional view taken on the line 12 12 of Fig.l0; and

Fig. 13 is a sectional View of a modified socket structure similar tothat shown in Fig. l0. I

Referring to Figs. l to 4, the socket member 1 comprises a body having arearward extension 2 forming the shoulder 3 that may be employed toattach the socket to a rotary chipping head or other device with the useof a cap nut or other similar device. The shoulder 3 may be employed toclamp the socket to the body or the latter may be welded or otherwiseattached to the member on which the socket is to be mounted The socket 1is provided with a bore 4 for the purpose of receiving the stem 5 of thebit 6. The bit body is provided with a transverse shoulder 7 arranged toengage the annular surface 8 that surrounds the bore 4 of the socket.Extending from the body of the bit 1 are a plurality of teeth 10 and 11.The tooth 10 is longer than the tooth 11, extending farther from thesocket than the latter. Both teeth are formed integralwith the bit andextend in opposite directions forming the V-shaped device in the centerthereof as indicated at 12. Such a bit could be employed as a centertool or pilot bit of a rotary chipping head. The bit, as shown in Figs.l and 2, was designed for the purpose of acting as a pilot bit rotatingin a counterclockwise direction when viewed from below in Figs. l and 2.The rear side of the teeth are backed otf as indicated at 13 providing anegative rake. The bore 4 may be square or rectangular in cross sectionand so in the mating stern 5 of the bit 6. This nonround bore transmitsthe rotary power to the complementary shaped bit stem.

The bit is provided with a pocket 14 on one side of the stem or shankthereof, the stem being preferably of square or rectangular crosssection as indicated in Figs. 3 and 4. The pocket 14 is arranged to openinto the window 15 of the socket 1 when the shoulder 7 of the bitengages against the annular surface 8 of the socket. Extending from thewindow or lateral opening 15 to the rear of the socket is an axiallydisposed recess 16 which is of sutiicient depth to receive the flexiblearm 17 made of spring material, making its outer surface ilush with thesocket surface. The flexible arm 17 is secured to the socket by means ofthe screws 18 and 19 which are fastened in threaded openings in thesocket 1. The outer end of the exible arm 17 is provided with aninwardly depending tongue 20 arranged to pass through the opening orwindow 15 into the pocket 14 in the side of the shank or stern 5 ofthebit. A transverse pry slot 21 is provided across the face of the socket1 and is lower than the recess 16 for the purpose of permitting theinsertion of a knife, screw driver or other type of sharpened implementfor the purpose of prying up the ilexible arm 17 to withdraw the tongue2G from the pocket 14, and thereby release the bit from the bore 4 ofthe socket.

The single toothed bit as shown in Figs. 5 to 8, wherein the bit 22 isprovided with the shoulder 23 that engages against the annular shoulder24 of the socket 25, shows the socket 25 Welded to one face of the arm26. The socket 25 has a bore 27 extending therethrough for the purposeof receiving the stem 28 of the bit 22. The stem 28 extends from theshoulder 23 to the end of the bore of the socket as illustrated in Fig.5. The socket 25 is provided with two oppositely disposed windows 3l)and 31 which are in alignment with each other. The recess 32, to receivethe spring locking arm, extends from the window 30 around the back ofthe socket to the window 31 for receiving the U-shaped ilexible arm orspring member 33 that has inwardly projecting tongues 34 and 35, thatengage in corresponding pockets on 25 is provided with theV transverseslots Y36 and 37- toreceive a sharpened implement for the purpose ofspreading the spring member 33 to withdraw the tongues 34 and 3 5 fromthe pockets in the sides of the stemV o the bit, thereby permitting thebit to be withdrawn from the socket.

t In the structure shown in Figs. 9 to 12, the socket member 40 issecured to the chipping head arm 41 and the top side ofthe socket isprovided with the spring arm recess 42 that extends along the top and`down the back of the socket as indicated in Fig. 10. 1n this show-` ingthe bit 43 is provided with the shoulder 4.4 and has two projectingteeth 45 and 46. The bit 43; is provided with the rearwardly extending.stem 47 that is square for the purpose of fitting the square bore 4S ofthe socket 4.0, The stem 47 is provided with a pocket 5t) that is inalignment with the window or opening 5l through one of the socket walls.This window is likewise at the, end of theA recess 42. The flexible armor spring 52, having the inwardly extending tongue 53, lies in therecess 42`and its tongue is arrangedl to engage through the window 51into. the pocket 50 of the stem of the bit. This exible arm or spring 52extends rearwardly and downwardly along the recess 42 and, back alongthe topV surface of the chipping head 41 and is secured thereto by thescrews 54. A transverse slot 55 is cut in the top surface of the socket40 for the purpose of permitting the insertion of a pointed implementunder the spring arm 52 to withdraw the tongue 53 from the pocket 50 andpermit the bit to be withdrawn from the bore 43 of the socket 4l). As inFig. 5, the bore 48 extends through the socket 4t) andthe rear end ofthe stem 47 is substantially covered by the spring arm 52. As in eachofl the structures previously described, the prying slot that extendsacross the face of the socket is cut below the recess to permit thesharpened implement to. be inserted underneath the spring arm. t

By thus properly disposingthe teeth on the bit with reference tothesocket in which it is to be inserted, the spring arm, which detachablyholds the bit or tool in the socket, is protected. from direct contactof the coal` Whenthe tool is in use. However, any pointed or sharpenedimplement may beemployed toflex the spring arm and thereby release the,bit from the socket. In each of the structures disclosed, the stem is ofrectangular cross section andy is inserted in a complementary bore in.the socket. Although there' is no clearance shown between the stemandthe boreof. the socket, such clearance is preferableY to permit readyinsertion or with-V drawal of the bit intothesocket.

The body or` head member 41, as shown in Fig. 13, is provided with thesocket 56'Which has a boreV 57 extending. therethrough for receiving theshank or stem 58 of the bit lill.y The bit llfis similar in design tothat shown in Figs. 9 and 10, with the exception that thewith atransverse clearance slot, but these parts are replacedby the pocket 63and the shoulder 64 within the body of the bit 60 and suicient clearanceis allowed below the tip of the tongue to permit the insertion of thepointed implement for the purpose of prying the tongue and exing thespring 66A so as to permit ready removal of the bit 60 from the socket56.

Thus, in thestructure as shown in Fig. 13, the pocket in the shank ofthe tool has been replaced by the pocket 6 3V in the'body of the bitwhich also functions as a transverse clearance slot forthe purpose ofprying the flexible arm to, release the bit from the socket.

While, for clarity of explanation, certain preferred embodiments of thisinvention have been shown and described; itis to' be understoodv thatthis invention is capable of many modifications, and changes in theconstruction and arrangement mayv be made therein and certain parts maybe employed without conjoint use of other parts and without departingfrom the spirit and scope of thisAv invent-ion@ We claim:

A holder for detaehable' mining machine bits comprising a squaretubularY socket having at least three outer hat` faces and mounted onthe arm of a miningA machine cutting h ead, a square bore in saidsocket, at least three lateral forceA transmitting surfaces around themouth of said bore and corresponding to saidy outer at surfaces, a bithaving a square body, a square shank extendingfrom the lower side ofsaid body and iitting in but shorter than saidsquare bore to retain saidbit from turning, and to transmit some of the digging forcesv off thebit to the Varmv of the cutting head, a pocket in the rear face ofsaidshank, a shoulder on at least three sides of said= bodyatitsjuncture with said shank, said shoulders mating-withsaid lateralvforce transmitting surfaces on saidY socket to transmit other of thedigging forces o1` tl 1e b it to the arml of the cutting head, toothmeansprojecting from the upper side of said bit body above the planeofsaidshoulders, alongitudinal recess extending the fullv length ofv theintermediate of said, outer atf surfacesV of said` socket, a-,liat bitretaining springvtttin-g-,in said recess and having one end securedrelative` to saidsocket, aninturned: tongue on the other end .of saidspringV extending intosaid bore and into said shank. pockete wheny saidshoulders engage said lateral` force transmitting surfaces, to preventaccidental displacenjlent of said bit from said socket, andl a pry slotin said outer( Hat. surface extending across and deeper thansaid.recess7 and inwardly of said tongue to receive a wedge underfsaid.springy to pry said tongue from said pocket to replace saidrbit.

References Citedin thele of this patent UNITED: STATES PATENTS

